Session: 33-22 Tutorial - Heat Exchangers for Supercritical Co2 Power Cycle Applications

Paper Number: 83734

83734 - Heat Exchangers for Supercritical CO2 Power Cycle Applications 

Heat exchangers in supercritical CO₂ (sCO₂) power cycles are key drivers of cycle performance, determining the capability of heat to be added/rejected from secondary sources and recuperated internally to increase cycle efficiency. An understanding of their strengths and limitations plays an important role in prudent decision making for overall sCO₂ power cycle implementation. Thermo-mechanical limits of a recuperator can have major influence on the turbine operating envelope, and decisions on heat exchanger sizing have a significant impact on overall loop capital cost. This tutorial begins with a brief overview of sCO₂ fluid properties, with insight into the validity of conventional approaches to analyzing heat exchangers. That overview is followed by discussion of sCO₂ power cycle configurations, going through thermodynamic roles of each heat exchanger and the main configurations considered for each. A design approach is then covered that contains multiple topics. The steps from definition of boundary conditions, to selection of heat exchanger configuration, to evaluation through a progression of analysis methods, are outlined. Optimization process examples are also given that demonstrate performance and size tradeoffs. The second part of the tutorial covers printed circuit heat exchangers (PCHEs) in depth including their diffusion bonding manufacturing process, material selection considerations, and hydraulic and structural design features. Attention is also paid to relevant operational problems in heat exchangers along with preventative measures and maintenance solutions. The third part examines primary heat exchanger and cooler design, and details examples of recuperator prototypes using additive manufacturing and high power laser cutting.  Heat exchanger test data from sCO₂ loops will also be presented. The tutorial attendee will walk away with an enhanced understanding of selection and design of heat exchangers specific to the conditions and requirements for sCO₂ power cycle application.

Presenting Author: Michael Marshall Southwest Research Institute

Presenting Author Biography: Michael Marshall is a research engineer in the Machinery Department at Southwest Research<br/>Institute. He earned his Bachelors in Aerospace Engineering from the University of Virginia. His<br/>research interests include the design of turbomachinery and heat transfer systems, power cycle<br/>development and modeling, and turbomachinery testing.

Authors:

Michael Marshall Southwest Research Institute
Renaud Le Pierres Heatric
Mebrahtu Embaye Heatric
Marc Portnoff Thar Energy